1. Field of the Invention
The present invention relates to an electrical card connector having a stand-off device, and particularly to an electrical card connector which can shield a fastener, which is employed to mount the stand-off device to a printed circuit board, from interfering other electronic devices. This application relates to the other two contemporaneously filed applications having the same title, the same inventor and the same assignee with the invention.
2. Description of Related Art
Electrical card connectors, such as PCMCIA (Personal Computer Memory Card international Association) card connectors, are widely used in computer industry for electrically connecting with inserted electronic cards which function as removable mass storage devices. To meet the trend of miniaturization and high-speed data transmission of computer technology, the electrical card connectors are developed to have a compact and high-density arrangement regarding contacts of the electrical card connectors, which may result in. EMI (Electromagnetic Interference) and ESD (Electro-static Discharge) problems, thereby adversely affecting electrical performance of the electrical card connectors.
In order to achieve better electrical performance, the electrical card connectors are equipped with grounding devices to ground the inserted electronic cards to a ground circuit of a printed circuit board on which the connectors are mounted. At the same time, the electrical card connectors often have stand-off devices for providing clearance between the connectors and the printed circuit board to thereby allowing components such as semiconductors to be mounted on the printed circuit board below the card connectors. Generally, the stand-off devices of the electrical card connectors also have grounding function. Thus, no additional grounding devices are required for the electrical card connectors. Examples of these conventional electrical card connectors are disclosed in U.S. Pat. Nos. 6,069,633, 6,231,382, 6,059,586 and 6,048,214.
A conventional electrical card connector 4 and a printed circuit board on which the connector 4 is mounted are presented. The electrical connector 4 comprises an insulating body in which a plurality of terminals are provided for electrical connection to the printed circuit board, a shield covering the insulating body and a pair of stand-off devices 44 attached to the shield on opposite sides thereof. Each stand-off device is generally of an L-shaped configuration including a retention portion and a terminal portion extending perpendicularly from a lower edge of the retention portion. The retention portion defines a first and a second slits (not labeled) for fitly receiving therein a first spring tab and a second spring tab of the shield, respectively, whereby the stand-off device is securely attached to the shield. The terminal portion has a projection defining a screw hole therein. A bolt is employed to upwardly extend through a positioning hole of the printed circuit board and then into the screw hole of the stand-off device, thereby fixing the connector 4 on the printed circuit board. It is noted that the terminal portion is also connected to a ground circuit of the printed circuit board for grounding purpose.
The bolt generally has a large lengthwise dimension for fixing the electrical card connector 4 to the printed circuit boards having various thickness. When the printed circuit board is thinner, a tail portion of the bolt extends beyond the projection and is mostly exposed above the printed circuit board. The exposed tail portion of the bolt has a risk of interfering other electronic devices, whereby a connection is easy to become loose between the connector 4 and the printed circuit board, which results in an unreliable electrical connection between the connector 4 and the printed circuit board. At the same time, the exposed tail portion of the bolt may scratch or even damage the electronic devices, thereby increasing the manufacturing cost.
Accordingly, it is an object of the present invention to provide an electrical card connector having a stand-off device, the connector being configured to prevent a fastener, which is employed to mount the stand-off device to a printed circuit board, from interfering other electronic devices.
In order to achieve the object set forth, an electrical card connector in accordance with the present invention comprises an insulating body in which a plurality of terminals are provided for electrical connection to a printed circuit board, a shield covering the insulating body, a pair of stand-off devices secured on opposite sides of the shield and a pair of shield members attached on the stand-off devices. Each stand-off device includes a retention portion secured to the shield and a terminal portion with a screw hole defined therein extending laterally from a lower edge of the retention portion for connection to the printed circuit board. The shield member defines a round hole aligned with the screw hole for receiving therein a tail portion of the bolt, thereby shielding the bolt from interfering other electric devices.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.